The present invention relates to an irrigation system usable with an angioscope.
The angioscope is a medical instrument for viewing inside the cardiovascular system. The most common application of angioscopy is to view the interior lumen of veins and arteries, although angioscopes have also been used to inspect the interior of the heart and other organs. The size of the vessels which can be inspected by angioscopy is limited by the outer diameter of the insertion portion of the angioscope. Vessels ranging from small coronary arteries to large peripheral vessels may all be inspected by the appropriate instrument.
An angioscope generally comprises an insertion portion in the form of a tube traversed in the longitudinal direction by an optical guide for transmitting light energy from an external source into the interior lumen of a blood vessel into which the insertion portion of the angioscope has been inserted. The insertion tube also carries an optical guide for transmitting light energy from a lens at the distal end of the insertion tube to an eyepiece or a video system for enabling observation of images from inside the blood vessel.
In order to obtain a visual image of an inner surface of a blood vessel, the blood within the vessel must be displaced. Generally, blood displacement is accomplished via the introduction of a clear fluid into the blood vessel in a region about the distal tip of the angioscope. Conventional irrigation systems require the full attention of an assistant of the endoscopist performing the angioscopy procedure. The assistant controls, under the supervision of the endoscopist, the pressure and flow rate of the clear fluid into the blood vessel under observation.
An object of the present invention is to provide, for use with an angioscope, an irrigation system which eliminates the need for the full attention of an assistant and, once the system is set up, can be operated under the complete control of an endoscopist performing an angioscopy procedure.
Another object of the present invention is to provide such an angioscope irrigation system wherein the amount of an irrigant infused into a patient is easily minimized.
Another, more particular, object of the present invention is to provide such an angioscope irrigation system wherein the flow rate of irrigant during an infusion operation can be precisely selected or preselected.
Another particular object of the present invention is to provide such an angioscope irrigation system wherein the operator is continuously provided with an indication of both the current flow rate and the total volume of irrigant infused.